Some electrophotographic printing devices operate by charging a surface of an image-forming drum to create a latent electrostatic image and developing the latent image by depositing charged ink particles onto the drum from an ink-bearing surface of a developer roller such that the charged particles are attracted to the desired areas of the drum. This developed image is then transferred from the drum onto a substrate, such as paper. A charged cleaner roller is provided to remove ink particles that remain on the ink-bearing surface of the developer roller after transfer of ink to the image-forming drum, thereby cleaning the ink-bearing surface of unused ink particles.
Over time, however, the conductivity of the developer roller can decrease. This has the effect of a surface of the developer roller not being charged to a target voltage. With a target voltage not being reached, the cleaning efficiency of the cleaner roller is reduced.
For rollers other than the cleaner roller, this decrease in voltage is compensated for by a color adjust procedure. However, this color adjust procedure does not compensate for the effects of the decrease in voltage on cleaning of ink from the ink-bearing surface of the developer roller.